At the top of the spectrum is the premium ALC885 high definition audio codec which joins Realtek's previous upper-end ALC882. New features of the ALC885 include support for a digital microphone, an improved ADC that supports 192 kHz sampling rates and a higher DAC signal-to-noise ratio of 106 dB versus the ALC882's 101 dB. The biggest feature addition is support for DRM protected content playback. Supported protected content include DVD-Audio, Blu-ray, and/or HD-DVD discs. Copy protected content will be capable of being played back at 24-bit resolution and 96 kHz sampling rates.
Existing features of the ALC882 are also integrated into the ALC885. This includes 10 DAC's for support of 7.1 channel audio as well as a dedicated headphone output, 6 ADC's for your various microphone, line, and CD inputs, and DAC sampling rates of 44.1/48/96/192 kHz.
The second new codec is the Realtek ALC888 with similar specifications to the previous ALC883 high definition audio codec. Digital microphone support seems to be the only new feature the ALC888 has over the ALC883. Aside from the digital microphone support the ALC888 supports the same specifications as the ALC883.
Lastly is the ALC888 Telecom which is essentially the ALC888 with additional support for VoIP services. VoIP support integrated into the ALC888 Telecom allows Skype or other VoIP service users to connect a standard telephone to their computer and make calls, essentially integrating a VoIP phone adapter like the ones used by Vonage into your PC.
The ALC885 and ALC888 are both pin compatible with existing ALC882, ALC883 and other 48-pin LQFP packaged high definition audio codecs. The ALC888 Telecom however, is not pin-compatible with existing high definition audio equipped motherboards and systems and uses its own 64-pin LQFP packaging.
